The goal of this Mentored Patient-Oriented Research Career Award (K23) is to provide Dr. Angela Pinto with the opportunity to develop the expertise needed to become an independent scientist studying cost-effective behavioral treatments for obesity. This training plan outlines a combination of didactic and direct mentored training experiences that will provide Dr. Pinito with the opportunity to develop and enhance skills in the following areas: the public health model of obesity and obesity treatment;behavioral approaches to weight regulation;methodology, statistics, and ethics of clinical obesity research;and the standards and techniques of cost-effectiveness analysis and their application to behavioral weight loss trials. Dr. Pinto will work closely with her primary mentor, Dr. Rena Wing, and her co-mentors, Drs. William Herman, Mark Schleinitz, Joseph Fava, and Robert Jeffery, throughout the course of this award. The resources at the Miriam Hospital/Brown Medical School, combined with the expertise of her mentoring team will provide Dr. Pinto with the ideal environment in which to achieve her training and research goals. Obesity is a major public health problem in the United States. University/hospital-based behavioral weight loss programs are the gold standard for moderate obesity, but they are costly to run and have limited accessibility to the majority of individuals seeking weight loss. Commercial weight loss programs offer widely recognized, highly accessible, and affordable treatment, but produce weight losses that are markedly less than those achieved in university/hospital based treatment. The scope of the obesity epidemic demands behavioral weight loss treatment that is both clinically effective and cost-effective for individuals who want to lose weight. Therefore, the purpose of this investigation is to develop and evaluate a cost-effective treatment for obesity that integrates the clinical effectiveness of behavioral weight loss interventions with the accessibility of the Weight Watchers commercial program. In this 12-month trial, 198 men and women with a BMI of 27-40 will be randomly assigned to receive standard behavioral weight loss, Weight Watchers, or a combination treatment. The long-term goal of this research is to expand the public health reach of cost-effective obesity treatment through increased collaboration between university/hospital-based behavioral weight loss programs and commercial weight loss organizations.